You have to locate another force sensitive person to test you. However, the odds of you being able to find a force sensitive person willing to test you are extremely low. Not only that, but the odds that you prove to be force sensitive are also extremely low.

It is recommended that you wait until you are given the opportunity to get tested (through your faction, etc) rather then trying to find someone yourself.

EDIT: Cesodevo Avina and I posted at nearly the exact same time...Sorry about being repetitive.